1. Field of the Invention
The present disclosure relates to a display device; in particular, to an organic light emitting display device.
2. Description of Related Art
Current organic light emitting display devices have relatively higher response speed, sharper color contrast, and barely any visual limitations in comparison to the conventional liquid crystal displace devices. Moreover, since organic light emitting display devices are self-emissive, backlight modules are not necessary, making the display device relatively lighter, less likely to be affected by external lighting in the ever changing environment, and compatible with indoor and outdoor uses.
Organic light emitting display devices typically include an upper substrate and a lower substrate. The lower substrate includes an organic light emitting element array and a thin film transistor array. The thin film transistor array controls the organic light emitting element array to display colored lighting in order to produces images. Typically, in the organic light emitting display device manufacturing process, an encapsulation layer covers over the organic light emitting element array after the organic light emitting elements array is completed on the lower substrate in order to prevent moisture intrusion, and in turn, reduce the service life of the organic light emitting elements. Successively, sealant structures or fillers are used when the upper and the lower substrate are pressed together to complete the packaging process.
During the production process of the organic light emitting display device, small particles having larger diameters than the thickness of the encapsulation layer are prone to remain on the lower substrate. Successively, after the encapsulation layer is formed on the organic light emitting element array, protrusions are generated at the outer surface of the encapsulation layer since the encapsulation layer entraps the small particles thereunder. When the upper and lower substrates are pressed together for assembly, the protrusions are prone to generate cracks or punctures at the encapsulation layer due to pressure when pressed against the upper substrate, which leads to moisture intrusion within the organic light emitting elements and reduction in service lives of the elements.
To address the above issues, the inventor strives via associated experience and research to present the present disclosure, which can effectively improve the limitation described above.